Assessment of green biocomposites based on polyvinyl alcohol and grafted biopolymer tamarind kernel powder with polyacrylic acid

Abstract

This investigation focuses on the development and assessment of biopolymer-based green biocomposite materials that contain tamarind seed kernel powder (TKP) either in its raw or polyacrylic acid (PAA) grafted form as the reinforcing component, combined with polyvinyl alcohol (PVA) as the matrix material. The goal is to develop biopolymer TKP based green biocomposites with a biodegradable PVA matrix for food grade packaging and biomedical applications. Both raw TKP reinforced PVA and PAA grafted TKP reinforced PVA, two forms of sustainable green biocomposites, were developed. Compression molding was used to combine various raw or PAA grafted TKP loadings with PVA to produce various biocomposites. The loadings were 0 %, 0.25 %, 0.5 %, 1 %, 5 %, and 10 % in weight. To confirm the PAA grafted TKP, attenuated total reflection-fourier transform infrared (ATR-FTIR) spectrum analysis was employed. The mechanical properties of the biocomposites were examined, and it was discovered that the grafted biocomposites exhibited 4 % higher tensile strength and elongation at break (%) on average than the raw TKP reinforced PVA biocomposites. The Charpy impact strength of the biocomposites exhibited an average 28 % improvement in impact resistance with modified TKP and an 8 % increase with raw TKP when compared to pure PVA sheets. Additionally, the PAA-grafted TKP reinforced PVA biocomposites outperformed the raw TKP reinforced PVA biocomposites in water absorption tests, exhibiting an average improvement in moisture resistance of nearly 13 %. Scanning electron microscopy (SEM) tests revealed that the PAA-grafted biocomposites had a more uniform dispersion of fillers inside the PVA matrix as compared to the raw TKP/PVA biocomposites. These findings enable in the development of high-performance, environmentally friendly and green biocomposite materials for a variety of uses.